Class 10 Science - Chapter How do Organism Reproduce? NCERT Solutions | Why is DNA copying an essential part of

Why is variation beneficial to the species but not necessarily for the individual?

Draw a labelled diagram of the longitudinal section of a flower.

What are the functions performed by the testis in human beings?

Why does menstruation occur?

How will an organism be benefited if it reproduces through spores?

Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?

Asexual reproduction takes place through budding in

(a) amoeba.
(b) yeast.
(c) plasmodium.
(d) leishmania.

What are the advantages of sexual reproduction over asexual reproduction?

How does the embryo get nourishment inside the mother’s body?

How does reproduction help in providing stability to populations of species?

Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.

What is a good source of energy?

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

What changes can you make in your habits to become more environment-friendly?

What is the difference between a reflex action and walking?

If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?

Why should a magnesium ribbon be cleared before burning in air?

Define the principal focus of a concave mirror.

You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?

Find the power of a concave lens of focal length 2 m.

A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R′, then the ratio R/R′ is –

(a) 1/25        (b) 1/5        (c) 5        (d) 25

What were the limitations of Newlands’ Law of Octaves?

What would be the electron dot structure of carbon dioxide which has the formula CO₂?

On what basis would you classify energy sources as

(a) renewable and non-renewable?
(b) exhaustible and inexhaustible?

Are the options given in (a) and (b) the same?

Compare and contrast fossil fuels and the Sun as direct sources of energy.

What is the role of the brain in reflex action?

The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

Find the focal length of a lens of power – 2.0 D. What type of lens is this?

Draw the electron dot structures for

(a) ethanoic acid.
(b) H₂S.
(c) propanone.
(d) F₂.